([Mathematical   formula   4]                                                                                             ((e 11e 21e 31))=↑As_ave/\[LeftBracketingBar]↑As_ave\[RightBracketingBar]   or(4a)((e 11e 21e 31))=-↑As_ave/\[LeftBracketingBar]↑As_ave\[RightBracketingBar](4b))